Electrostatic precipitators



E. 1.. RICHARDSON ELECTROSTATIC PREC'IPITATORS Feb. 4, 1958 4Sheets-Sheet 1 Filed June 27, 1955 Feb. 4, 1958 E. L. RICHARDSONELECTROSTATIC PRECIPITATORS Filed June 27, 1955 4 Sheets-Sheet2 UnitedStates PateneO ELECTROSTATIC PRECIPITATORS Earl L.Richardson, Hyde Park,Mass., .assignor to W'est-. inghouse ElectrieCorporation, EastPittsburgh, Par, a corporation of Pennsylvania Application June 27,1955, Serial No. 518,077

2Clainis. (Cl. 183-7) This invention relates to electrostaticprecipitators 'havingdisposable collector cells ofoflexible sheet-likematerial, and-has as an object to. stiffen such, cells ,when...

such a cell when the cell-is inoperating'positionwhereby the walls. aremaintained under tension with theirassociated collection surfacesproperly spaced. and-inalignment.

This invention will now be describedwith reference to the annexeddrawings, of which:

When such a cell. is placed.:within..

Fig. l is a frontelevation of an electrostatic precipitator containingfour collector cells embodying this invention; Fig. 2 is anenlarged-front section: :of one'of: :thecells ofFig. l, thesectionbeing-along the line 2..-2 of Fig. 3;

Fig. 3 is a section along the line 3-3 of. Fig.2;

Fig. 4 is a planview of one of the cell stretching platesused in Figs.1-3;

Fig. 5 is a side elevation of the plate of Fig. 4; Fig. 6 is an end viewof the plate-of zFigs. 4 and 5; Fig. 7 is a side section,alongtthe'rzline 77 of-Fig. 8,

of. another embodiment of thisginvention, the:,.collector'- cell beingomitted, and the cell stretcher being in nonstretching position;

Fig. 8 is a front section along the line 8-8 of Fig. 7;

Fig. 9 is a side section similar to Fig. 7 but with a collector cell inposition, and a cell stretcher in stretching position, the section beingalong the line 99 of Fig. 10;

Fig. 10 is a section along the line 10-10 of Fig. 9, and Fig. ll is afragmentary section along the line 11-11 of Fig. 9.

The collector cells shown by the drawings are generally similar to theone disclosed in my said patent, and are constructed of electricinsulating material such as thick paper, cardboard and the like, withmetal foils cemented thereto or coated thereon.

Referring first to Figs. l6, each cell has an outer wall 12 forming thetop, bottom and sides of the cell. A metal foil 13 is aflixed to theinner surface of the outer wall except at its bottom and near the bottomof its left side (facing Fig. 2). A similar foil 15 extends along theinner surface of the bottom of the cell but is omitted near the rightand left sides of the cell. The foil 13- where it extends along theinner surfaces of the left and right sides of the cell for-ms its outercollector plate surfaces. The other plate surfaces having the samepolarity as the foil 13 are formed by foils 17 which are aflixed toalternate vertically extending inner cell walls, the foils 17 beingelectrically connected to the foil 13. The collector plate surfaceshaving the opposite polarity are formed by foils 18 affixed to the2,822,057 ."Patented Feb. 4, 1958 other-vertically extending'innercelLwalls, and Whichare electrically connected to'the foil-15.

Thepelkwallshaving the ,foils 18- thereonhave turnedover horizontally:extending stubv portions 20 at .the .bot-

:torn ofothe-eell =with. foils 18 on their upper-surfaces.

The ,cell walls having the foils 17 thereon have turnedoversstubportions 21 at the top, of the cell with gfoils 17Jontheirlowersurfaces. t.

For preventing-theflexibleywalls of sucha ce lfr bending when, thecell-is placedsin operating; position, upper and lower metal.stretching. plates 22 and r 23; respectively, ,are provided; The plate22has spaced apart spring-fingers 24,. along-its sides whichhavetcellecontacting portions :.below the plate andextendinginwardly of,its

.sides-incontact. with. the foil17.- on the bottoms ofthe stuhportions21 at .the frontandeback of ,the-celLEtA pair of similarfingers 24Acontact. the zbottom-rsidevof thezrfoilwlliaon the'under surface.of'the-v topofpthe; cell at its. -left .side.-,

The.plate-,23..has .spaced apartl spring fingers 25;al011g itsssides'.which, have cell contacting portionsabove. the plate:andzextending.inwardlypf its sides in contact with the foils..18. onthe-tops. of-the stub portions;20,..ata the frontrand back of the cell.

The..cell stretchingplates- 22 and 23 have channels 26;..and .27.vrespectively, which extend across their. .top and bottomrespectively,beyond the rendsof the11-plates;

Referring now-toFig. 1 of the drawings; a rectangular .casing29 havingfour .cell compartments,-;isx:con

,structed ofielectricalinsulating material such as;;Bakelite,

Formica or other suitable material, and has a, central verticallyextending innenwall- 3041f, the' same material. Attached to t. the:inner :surfacesrof'; the; Tight-andJeft-JSiGe of the casings, and: tothe opposite. 1, sidesofrthe; central wall.30.a-djacent.thetop of. the,casing-:are aligned, horizontally extending metal shelves 31; ovenwhich:are placed the. ends. .of': thechannels .26, of. the upper "cellstretching platest22. of. the two. upper cells.- .Attached: to-the innersurfaces ,ofwthettright. and left sides-of; the .;casin'g :and

.to..the..opposite. sides..of the :central W311i \at..their centers.are-metal brackets-.32, thetuppergportionsuof which; form. alignedhorizontally t extending shelv.es.; 33 under which the ends of thechannels 27 of the lower cell stretching plates 23 of the two uppercells are placed.

The brackets 32 also form aligned horizontal shelves 34 just below theshelves 33 and which support the ends of the channels 26 of the uppercell stretching plates 22 of the two lower cells.

Attached to the inner surfaces of the right and left sides of the casingand to the opposite sides of the central wall 30 adjacent the bottom ofthe casing are the aligned metal shelves 35 under which are placed theends of the channels 27 of the lower stretching plates 23 of the twolower cells.

To place the channels of the upper and lower stretching plates of a cellin contact with their associated shelves requires the stretching of thespring fingers which support the upper and lower walls of the cell.Thus, the upper and lower walls of the cell are tensioned upwardly anddownwardly respectively, moving slightly apart sufiiciently to stretchthe vertically extending inner walls to which the foils forming thecollector plate surfaces are attached. The collector plate surfaces arethus maintained in parallel relation.

The brackets 32 attached to opposite sides of the central wall 30 areelectrically connected by a rivet 39 extending through the wall. Theshelves 31 attached to opposite sides of the central wall 30 areelectrically connected by a rivet 40. The shelves 35 attached toopposite sides of the wall 30 are electrically connected by a rivet 44.With the cells in operating position, corresponding horizontally alignedbrackets and shelves are the lower cells to the same positive terminal.

3 electrically connected by the channels of the stretching plates andthe rivets.

An outer bracket 32 can be connected to the positive terminal, say the+10 kv. terminal of the power pack, and through the brackets, the rivetsconnecting the intermediate bracket, and the associated channels, willconnect the foils 18 of the upper cells and the foils 17 of Outershelves 31 and 35 at one side of the casing, say the right side, can beconnected to the negative terminal of the power pack and to ground, andthrough the shelves, the rivets connecting corresponding intermediateshelves, and the associated channels, will connect the foils 17 of theupper cells and the foils 18 of the lower cells to ground. Thus, thefoils 13 of the two upper cells will form the charged plate surfaces ofthe upper cells with the foils 17 of the upper cells forming thegrounded plate surfaces, and the foils 17 of the two lower cells willform the charged plate surfaces of the lower cells with the foils 18forming their grounded plate surfaces.

Figs. 7-11 of the drawings illustrate another embodiment of thisinvention in which each collector cell has its own insulating casing 50.Spaced-apart metal straps 41 extend from the air outlet side 42 of thecasing where they have bent-over portions contacting the top of thecasing, to the air inlet side 43 of the casing, open spaces 44 beingformed between the straps and the top of the casing. A correspondingnumber of straps 45 are pivoted at 46 at the bottom of the air outletside of the casing, and their front ends are adapted to be engaged bythe latches 48 which are pivoted at 49 at the bottom of the air inletside of the casing, when the front ends of the straps 45 are pulleddownwardly as shown by Fig. 9.

Figs. 7 and 8 show an empty casing with the straps in cell receivingposition. A cell is slid into the casing through its air inlet end, thetop of the cell passing into the spaces 44, and the bottom of the cellpassing into the spaces between the straps 45 and the bottom of thecasing. With the cell in position, the front ends of the straps 45 areswung downwardly and engaged by the latches 48 as shown by Figs. 9 and10. The straps 41 contact rivets 51 which extend through foils 18 andupper turned-over stubs of alternate, intermediate vertically extendingwalls, and the straps 45 contact rivets 52 4 which extend through foils17 and lower turned-over stubs of the other intermediate, verticallyextending cell walls. The pull on the cell walls by the straps 41 and 45stretch the vertically extending cell walls to which the foils areattached, causing their collector plate surfaces to be maintained inproper parallel relation.

The straps 41 can be connected to a terminal of one polarity of asuitable power pack, and the straps 45 can be connected to a terminal ofthe opposite polarity for charging the foils 17 and 18 oppositely as inthe case of Figs. l6.

While embodiments of the invention have been described for the purposeof illustration, the invention is not limited to the exact apparatus andarrangement of apparatus illustrated since modifications thereof may besuggested by those skilled in the art without departure from the essenceof the invention.

What is claimed is:

1. An electrostatic precipitator comprising a casing, a collector cellin said casing, said cell having a pair of oppositely positioned wallswith a plurality of spaced apart flexible electrode supporting sheetsextending therebetween, said sheets having conductive surfaces formingcollector electrodes, a pair of plates, one plate extending across theouter surface of one of said walls and the other plate extending acrossthe outer surface of the other of said walls, a plurality of fingersformed on said plates at the interior surfaces of each of said wallsbetween said sheets, the fingers on one of said plates being of springmetal, shelf means in said casing, one of said plates being supported bysaid shelf means, other shelf means in said casing, said other platebeing supported by said other shelf means, said plates being moved apartin being supported by said shelf means and causing said fingers to movesaid walls apart so as to stretch said sheets.

2. An electrostatic prccipitator as claimed in claim 1 in which thefingers on the other of said plates are of spring metal.

References Cited in the file of this patent UNITED STATES PATENTS930,561 Rahe Aug. 10, 1909 1,049,789 Williamson Jan. 7, 1913 RichardsonJuly 22, 1952

